Oil conversion using superior catalytic masses



Jam:12,'1943 K K. KEARBY H y 2,307,795 OIL CONVERSION USING SUPERIOR CATALYTIQ MAssEs Filed Dec., 14, 193s' Patented Jan. 12, 193 l Y #UNITED I STATE s wrrlazN'r-oFFicli;

OIL CONVERSION USING SUPERIOR CATALYTIC MASSES l I Kenneth x. nearby, Elizabeth, N. :..asngnor to Standard ll Development poration of Delaware Application December 14, 193s-, serial No. 245,156() Company, a corz calms. (ci 19e-sz) This invention deals with the use of activated natural clays as catalysts for various chemical magnesium, calcium, alkali metals, titanium, etc.

Certain of .these natural clays, aS exemplified byl fullers earth, cannot be improved in activity to any substantial extent by acid or alkali treatment.

` Other clays such as bentonites show a remarkable increase in activity when a portion of the clay mineral is removed lby leaching with acids, generally dilute acids such as hydrochlorick or sulfuric. It is withV these latter clays that this invention is concerned.

Activated bentonitic clays have been-used in the prior art for various catalytic reactions such as cracking and dehydrogenation. The art has also realized that at the elevated temperatures employed -i00l000` FJ, these clays become gradually coated with a carbonaceous deposit which subsequently causes substantial loss in activity. Such inactivated clays have been satisfactorily regenerated bythe use of air together I with steam at sui'ciently high temperatures to effect combustion of the impurities. In many instances ordinary ilue gas containing substantial amounts of moisture has also been employed together with a small amount of air for this purpose, Aand satisfactory regeneration has been effected in this manner.

In the art, raw bentonitic clays have been activated by treatment with dilute acid (e. g.' 530%. H2804) up to a -point Vwhere asmuch as 30% of the impurities have been' removed. By impurities is meant any ingredients other than alumina and silica present in the raw earth prior to acid treatment. Such treatment has been employed Y for the manufacture of commercial Filtrol which appears to be the only activated bentonitic clay produced commercially in this country. A

If cracking of petroleum hydrocarbons is considered, itis found that the activity of the treated clay rises with increase in acid treatment and I as the amount of impurities removed is increased, until a maximum point is reached after which the activity drops with further acid treatment. This can be more readily understood by reference tocurve A--B-C givenin Fig. l of the accompanying drawing. It will be observed that the amount of gasoline of l0 lb. Reid vapo'r pressure obtained by passage over the clay (Polkville clay in this case) increases until a maximum of about 39% gasoline is obtained, whenl about 58-61% of impurities are removed by the acid treatment. Further acid treatment causes a reduction in the amount of gasoline obtained until, when 'about 84% of impurities are removed, only about 20% of gasoline is produced. The raw material Y cracked in this case was West Texas gas oil, the

cracking temperature being 850 F. Curve A-B-C shows the activity ofthe clay after successive regeneration by the usual method em-v ploying steam and-air as the regenerating medium. In a commercial unit, therefore, the ob` vious operation would be to -employ an acid treatment corresponding to a point at the maximum value. v

According to this invention, under certain regeneration conditions, more eifective catalysts have been obtainedA by carrying the acid treat-- ment further past the so-called optimum point which has just been discussed. However, these 1 over-treated catalysts are very sensitive to steam during the regeneration operation, losing their activity rapidly and permanently. This high activity can be retained almost indefinitely by avoiding the use of steam during the regeneration operation. Whenregeneration (which may be advantageously carried out under a pressure of about '2*-20 atmospheres) of the over-activated? catalyst iscarried out in asllbstantial absence of water vapor and preferably in an inert atmosphere of nitrogen or carbon dioxide containing a small amount of oxygen (say 210%) an activity curve is obtained corresponding to curve A-B--D shown-in Fig. 1. Hence, by this particular treatment and regeneration, it has been possible to remove as much as impurities from the raw clay `and yet obtain gasoline yields as high as 43%, provided moisture is excluded from the regeneration gases.

. the yield of stable gasoline was 29.2%,

' timum at a treatment ample 1 was treated fifth cycle in this case line was 39.5% by volume.

" ample. Thisclay gave,

ot clay giving a treated clay having the following analysis:

Per cent SiO: 77.60 L01 15.77 Fenna 1.64 T101 0.35 Mg@ 4.06 CaO 0.31 Naro 0.04 KaO 0.1i This clay was also employed as a catalyst for cracking of West Texas gas oil under the same conditions of operation and regeneration as given in Example 1. A .Atthe end oi the fourth cycle while at the end of the sixteenth` cycle the yield was 28.7%. .It will be noted that these yields are lower than those given inthe previous example, showing that the clay activity reached an op- 'corresponding to about 1.05 lbs. of acid per pound o! clay.

Example 4.--A sample oi-raw Polkville clay having the same analysis as that given in Exwith 0.35 1b. of acid per pound of clay (diluted to 8% conc), and sub-- mittedto the cracking of West Texas gas oil under the same conditions as those given in Example i. vThe regeneration of this ktreated clay, however. was carried out in the substantial absence o! steam, the regenerating medium being air dlluted with nitrogen. it the end oi the fourth cycle the yield oi stable gasoline amounted to 36.5%. AExample 5.-In this experiment the raw Polkville clay was treated with 1.05 lbs. of acid per pound as in Example 2. and the regeneration was carried out in the absence of steam as described in Example 4. The yield oi stable gasoline at the end of the fourth cycle amounted to 39.5% by volume.

isexcludedduring treating with exclusion or steam from the regeneration gases has produced a higher conversion to gasoline than any of the previous examples.

The last tour experiments show that` if steam regeneration, 'the activity or the regenerated clay increases with increase in acid treatment of the clay up to the highest acid .treatment given in Example '1, whereas the treated clays regenerated with steam and air as shown by-Examples 1 to -3 appear to go through an optimum point for the acid treatment which optimum point is lower thanthe yield given in Example?, using a clay which would normally be considered an over-treated clay. The term Ioven-treated. clay in this specincation is used to designate clays obtained after drastic treatments-the amount oi reagent employed being more than that necessary for obtaining,` an opexamples or to any theory trampled- The Polkville clay ywas treated with 1.40 lbs. of acid per ample 3 and regenerated as described -in Example 4.

pound of clay as in Exin the absence oisteam At the end o! the the yield oi stable gaso Example 7.-'-Treating the Polkville clay of Example 6 even more strongly, a removal of '10% of the impurities was effected as compared to 60% removed by the treat given in the previous exunder similar testing conditions in the absence oi moisture, a conversion to stable gasoline ot 43%. 'It is thus apparent that this combination of ya high degreev of acid timum activity when employed.

Various other modiilcations and alterations may be made within the spirit and scope of the invention, but the invention is not limited to any or mechanism ci opiollowing claims in which the invention as broadly steam-air regeneration is eration. but only to the it is intended to cover as the prior art permits:

I claim:

1. In the catalytic conversion of hydrocarbon oils wherein the conversion is effected in the presence of acid activated clays and wherein said clays are subjected to periodicregenerating treatments with an oxidizing gas to remove carbonaceous deposits formed during the conversion operation, the improvement which comprises employing as a catalyst in said process a bentonitic clay which in raw state has been pretreated with` a diluted strong mineral acid in an amount to remove over 50% of its original impurltieshanci carrying out the regeneration of said clay in the absence of a substantial amount oi water vapor.

2. In the catalytic conversion oi hydrocarbon oils wherein the conversion iseiIected in the presence voi acid activated clays and wherein said clays are subjected tol periodic regenerating treatments with bonaceous .deposits formed during the conversion operation. the improvement employing as a .catalyst in said process a bentnnitic clay which in raw state has been presulfuricacid in an amount treated with diluted to remove over 50% oi its impurities and carrying out the regeneration o! said clay in the absence o a substantial'amoimt of water vapor.

KENNETH K. KEARBYL an oxidizing gas to remove carwhich comprises 

